In large scale electrical circuits, such as those used in the power generation industry, there are inherent problems in connecting some different conductors in the circuits. One of the problems is that some electrical conductors will move independently of one another. This difference in movement can be caused by the conductors experiencing a difference of temperature, vibration or other environmental factors. If an electrical connection between two conductors that move with respect to each other is rigid, then the electrical connection may wear rapidly and even break. Consequent overheating or electrical arcing at a degraded or broken electrical connection can cause severe damage to the connection itself, to the adjoining electrical conductors, and to the rest of the apparatus that houses the conductors.
FCA's have therefore been used to connect larger conductors electrically while allowing a difference of movement therebetween. One type of flexible connection, typical in water-cooled generators, is shown in FIG. 1. In this figure, a first electrical conductor (or lead) 2 is connected to a second electrical conductor (or lead) 4 via the FCA 6. The FCA comprises a series of electrically conductive and mechanically flexible connectors 8 that act as a mechanically flexible electrical bridge between the two electrical conductors. Differences of movement between the two conductors 2, 4 can be readily absorbed by the FCA 6.
Since large electrical currents need to pass through the FCA 6, multiple flexible connectors 8 are arranged in parallel to attempt to spread the current evenly across the FCA. However, electromagnetic phenomena that are inherent in such paralleled conductor assemblies cause the total current from one of the conductors 16 to pass in greater proportion through the outside flexible connectors 12, than through the inside flexible connectors 14. Therefore, the effective maximum current that this type of FCA can carry is limited since increasing the number of paralleled flexible connectors 8 has a diminishing improvement on the current capacity of the FCA. Further, the flexible connectors on the outer edges of the FCA wear proportionally faster than the interior flexible connectors since they carry a greater portion of the electrical current. This uneven distribution of current reduces the life expectancy of the FCA.
One technique for attempting to more evenly distribute the current among paralleled flexible connectors has been to arrange the flexible connectors circumferentially, as shown in FIG. 2, instead of linearly. In this figure an FCA 6 comprises a series of flexible connectors 8 that are evenly spaced circumferentially around the top plate 3 and the bottom plate 5 of a polygonal FCA. Current 16 passing from one conductor 2 to another 4 is now evenly distributed 18 among the various flexible connectors 8. A given FCA, however, is not used by itself, and each FCA will have multiple neighbors as part of a generator terminal assembly, as shown in FIG. 3. The electrical currents traveling through neighboring conductors may adversely affect the distribution of current among the flexible connectors within a given FCA.
FIG. 3 illustrates an example of an interior assembly of generator terminals 25. The conductors 2, 4 are centered in the FCA with the intent to evenly distribute the current load among the flexible connectors in the FCA. However, the electrical current 16 in each of the conductor assemblies 6 creates a magnetic flux 22. This flux interferes with the distribution of the current in the flexible connectors 8 in the neighboring conductors, causing an uneven distribution of the current among the flexible connectors.
What is needed is an FCA that evenly distributes electrical current among its component flexible connectors given the disrupting effects of its neighbors to thereby provides an increased overall current capacity.